Linux drivers on 6991SE - High Frequencies

[jpeg73]

Dear
I'm using TBS6991 With ubuntu14.04 +VDR+VNSI + Legal subscription
When I zap from channels, I observe always switching to high frequency like La2_h12721 cause issue
If I want to see descrambled channel on La2_h12721ASTRA
I ve to switch first on lower frequency like Fr3_h11681HOTB
Both are handled by legal subscription

Did you experienced driver issue with higher freq ?

Thanks in advance
JP